cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A240280 Number of nX3 0..3 arrays with no element equal to one plus the sum of elements to its left or two plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest, modulo 4.

Table of values

n a(n)
1 2
2 19
3 80
4 262
5 1461
6 5443
7 24490
8 117962
9 459193
10 2147788
11 9481211
12 39404594
13 181740410
14 780110007
15 3374455576
16 15188622683
17 65126163196
18 286616870440
19 1266986470030
20 5476212217332
21 24183642014347
22 105926526183355

List of values

[2, 19, 80, 262, 1461, 5443, 24490, 117962, 459193, 2147788, 9481211, 39404594, 181740410, 780110007, 3374455576, 15188622683, 65126163196, 286616870440, 1266986470030, 5476212217332, 24183642014347, 105926526183355]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.